针对多用户正交频分复用(OFDM)系统功率优化问题,提出一种高效的子载波、比特分配算法.该算法基于最小化-最大者(Min-Max)的原则逐个分配子载波,使用户功率递减;采用注水原理分配比特,使用户功率最小化;最后使用贪婪算法将分配比特取整,以实现系统功率最小化的目标.理论分析和仿真结果表明,本算法有效地降低了系统发射功率和运算复杂度.
A scheme of subcarrier-bit allocation is proposed for power optimization in multiuser orthogonal frequency division multiplexing(OFDM)system. The scheme allocates the subcarriers to reduce the power of users with the principle of Min-Max, and allocates the bit by water-filling to minimize the power of users. Finally the bit is rounded by greedy algorithm to obtain the minimized total transmit power of the system. Analysis and simulation results show that the performance is improved but with low complexity.